Insertion tool for rehabilitation tubular liner in pipes and pipelines

ABSTRACT

A method and apparatus for inserting a tubular liner impregnated with a hardening resin into the conduits or pipes to be rehabilitated is disclosed. The apparatus is a tool comprising a cylindrical segment and a conical segment, the cylindrical segment and the conical segment connected together to form a passageway adapted to guide a tubular liner inside a host pipe.

FIELD OF THE INVENTION

The present invention relates to a method and apparatus forrehabilitating underground conduits or pipes and more specifically to amethod and apparatus for inserting a tubular liner impregnated with ahardening resin into the conduits or pipes to be rehabilitated.

BACKGROUND OF THE INVENTION

Underground and surface pipes, either potable water pipes, waste waterpipes or sewer pipes, are typically made of rigid materials such asreinforced concrete, cast iron, ductile iron, steel and hard polymerssuch as PVC, HDPE, etc., that are durable and adapted to resist internalfluid pressure and the external pressure of the weight of the soil abovethem. Underground and surface pipes networks provide essential servicesto homes and businesses and have been deployed in cities, towns andvillages for more than a century. Buried and surface pipes connectedtogether in a network extends over long distances, spreads out in alldirections to provide services to residential homes or businesses over awide area. Underground and surface pipes are subject to normal wear anddegradation over extended periods of time due to cyclical loads, earthmovements, corrosion, increased porosity, cracks and overalldeterioration. As a result of their long service life, underground andsurface pipes will become damaged and require repair or replacement.

Replacement of damaged sections or portions of a pipe network is anexpensive, disruptive and time-consuming operation requiring heavyequipment for accessing, removal and replacement. Replacing oldernetworks of underground water conduits with new ones is unrealisticbecause of the sheer magnitude of the work that would be involved and isavoided as much as possible. However, repairing and rehabilitatingexisting water networks without the need to excavate represents afeasible alternative. Methods exist for repairing the walls of pipes andother conduits. One such method involves the use of a tubular linerimpregnated with a cured-in-place resinous material, referred to ascured-in-place pipe (CIPP) which re-lines the inner walls of the conduitor pipe to repair the network of conduits or pipe. The liner isimpregnated with a resin capable of curing and hardening to form a newinner wall for the aging or damaged pipes. A length of CIPP liner isinserted in the conduit or pipe and is pulled inside the conduit or pipethrough a specific segment of the conduit or pipe from one entrancepoint to an exit point. Once in place, pressurized water is introducedinside the CIPP liner to press the CIPP liner against the pipe wall. Theresin is then allowed to cure and harden, thereby creating a new sealedinterior pipe wall.

The tubular liner is typically a flat textile material or felt materialwhich is rolled into tubular form and stitched along its seam or aseamless tubular textile jacket made of warps and wefts woven intotubular form. When the tubular liner inserted into the entrance point ofthe conduit or pipe and pulled inside the segment of the conduit or pipeto be rehabilitated, the tubular liner often drags on the edge of theconduit's entrance opening thereby increasing the force required to pullthe length of tubular liner through the segment of the conduit or pipe.In the process, the tubular liner end up being stretched unevenly overits length, it may form folds and wrinkles and it may get damaged.

Tubular liners made of rolled material stitched along the seam areparticularly vulnerable as the seam is the weak portion of the tubularliner and the stitches may break under load thereby ripping the tubularliner at the seam and creating gaps which render the rehabilitation ofthe underground or surface pipe ineffective. Seamless tubular textilejackets are stronger because they do not have a seam that can be tornapart. However, seamless tubular liners may be unevenly stretched orwrinkles, bulges and/or folds may be formed when the seamless tubularliner is pulled and dragged on the edge of the conduit's entranceopening and the quality of the rehabilitation liner once cured may beaffected.

Thus, there is a need for a method and an apparatus for inserting atubular liner into a host conduit or pipe to be rehabilitated thatprevents stretching, wrinkling, bulging, folding or damaging the tubularwhen it is pulled inside the host conduit or pipe.

SUMMARY OF THE INVENTION

It is an object of the present invention to ameliorate at least some ofthe inconveniences present in the prior art.

In one aspect, the invention provides an insertion and guiding toolcomprising a cylindrical segment having an edge and a conical segmenthaving an edge, the cylindrical segment and the conical segmentconnected together at their edges to form a passageway adapted to guidea CIPP tubular liner inside a host pipe.

In an additional aspect, the insertion and guiding tool comprises atleast one anchoring device adapted to secure the tool onto an opening ofa host pipe.

In an additional aspect, the invention provides a method of inserting aCIPP tubular liner into a host pipe comprising the step of reducing thewidth of the CIPP tubular liner using a conical insertion toolpositioned at the opening of the host pipe.

Embodiments of the present invention each have at least one of theabove-mentioned objects and/or aspects, but do not necessarily have allof them. It should be understood that some aspects of the presentinvention that have resulted from attempting to attain theabove-mentioned objects may not satisfy these objects and/or may satisfyother objects not specifically recited herein.

Additional and/or alternative features, aspects, and advantages ofembodiments of the present invention will become apparent from thefollowing description, the accompanying drawings, and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, as well as otheraspects and further features thereof, reference is made to the followingdescription which is to be used in conjunction with the accompanyingdrawings, where:

FIG. 1 is a perspective view of an insertion and guiding tool inaccordance with one embodiment of the invention;

FIG. 2 is a side elevational view of the insertion and guiding toolillustrated in FIG. 1;

FIG. 3 is a top plan view of the insertion and guiding tool illustratedin FIG. 1;

FIG. 4 is a schematic side elevational view of a work site in which atubular liner is inserted and guided into a host pipe using theinsertion and guiding tool illustrated in FIG. 1; and

FIG. 5 is a schematic top plan view of the work site illustrated in FIG.4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1, 2 and 3, there is shown an insertion andguiding tool 10 in accordance with a preferred embodiment of theinvention. The insertion and guiding tool 10 includes two main portions:A cylindrical insertion segment 12 adapted to fit inside the opening ofa host pipe and a conical guiding segment 14 or lip adapted to guide atubular liner inside the host pipe by gradually and smoothly reducingthe width of the tubular liner to fit inside the host pipe andprotecting the tubular liner from the edges of the opening of the hostpipe. The cylindrical insertion segment 12 is preferably made of a sheetmetal approximately 0.1 inch thick which is bent in the form of anapproximately ⅔ cylinder leaving an opening 18. Similarly, the conicalguiding segment 14 is preferably made of a sheet metal approximately 0.1inch thick which is bent in the form of an approximately ⅔ conical lipdefining an opening aligned with the opening 18. The edges of the twosegments 12 and 14 have similar profiles and are typically welded orriveted together at their junction 20 to form a passageway 19 for atubular liner. The preferred embodiment of the insertion and guidingtool 10 is made of sheet metal however, other materials such as moldedplastics or composite may be used.

The outer diameter of the cylindrical insertion segment 12 isspecifically adapted to fit inside a host pipe having a specificdiameter. For example, for a host pipe having an 8 inch inside diameter,the outer diameter of the cylindrical insertion segment 12 would beapproximately 7.8 inch to ensure easy installation.

Fasteners or anchoring devices 16 a, 16 b and 16 c are positioned alongthe outer circumference of the insertion and guiding tool 10, at thejunction 20 of the cylindrical insertion segment 12 and the conicalguiding segment 14: A first and second anchoring device 16 a and 16 bpositioned on each side of the insertion and guiding tool 10, and athird anchoring device 16 c positioned at the bottom of the insertionand guiding tool 10. As illustrated in FIG. 3, each anchoring device 16a, 16 b and 16 c consists of an anchor 22 made of steel having a leg 23spaced apart from the cylindrical insertion segment 12 and a bolt 24inserted through a threaded hole (not shown) in the leg 23.

With reference to FIGS. 4 and 5, in operation, the insertion and guidingtool 10 is inserted into the opening 32 of an underground host pipe 30to be rehabilitated with a CIPP tubular liner 40 whereby the conicalguiding segment 14 protrudes from the edge of the opening 32 and coversthe edge of the entrance or opening 32 of the underground host pipe 30.The legs 23 of the anchoring devices 16 a, 16 b and 16 c extend outsidethe host pipe 30 and the insertion and guiding tool 10 is secured to thehost pipe 30 by tightening the bolts 24 of the anchoring devices 16 a,16 b and 16 c.

The CIPP tubular liner 40, which is still in a flat state, is routedfrom aboveground through a series of rollers 45 down to the entrance oropening 32 of the host pipe 30. The flat CIPP tubular liner 40, which iswider than the opening 32, is then bent manually to reduce its width andinserted into the passageway 19 of the insertion and guiding tool 10 andguided inside the host pipe 30 where it assumes a partially circularshape 40 a. The opening 18 is preferably positioned upward to provideeasier access to technicians for inserting cables and other equipmentfor example. The CIPP tubular liner 40 a is pulled via a cable or othermeans as indicated by arrow P.

The conical guiding segment 14 of the insertion and guiding tool 10guides the CIPP tubular liner 40 into the host pipe 30 by gradually andsmoothly reducing the width of the CIPP tubular liner 40 to fit insidethe host pipe 30 and simultaneously prevents the CIPP tubular liner fromdragging on the edge of the entrance or opening 32 of the host pipe 30thereby protecting the CIPP tubular liner 40 from potential damage fromthe edges of the opening 32. Furthermore, the guidance and gradualreduction of the width of the CIPP tubular liner 40 by the insertion andguiding tool 10 prevents uneven stretching of the CIPP tubular liner 40caused by uneven friction with the edge of the opening 32 and alsoprevents the formation of wrinkles, bulges and/or folds on the CIPPtubular liner 40 when the latter is pulled inside the host pipe 30thereby ensuring a high quality CIPP rehabilitation liner once cured.

The insertion and guiding tool 10 also has the beneficial effect ofreducing the force P required to pull the length of CIPP tubular liner40 through the host pipe 30 as it reduces friction at the opening 32 ofthe host pipe 30.

Modifications and improvements to the above-described embodiments of thepresent invention may become apparent to those skilled in the art. Theforegoing description is intended to be exemplary rather than limiting.The scope of the present invention is therefore intended to be limitedsolely by the scope of the appended claims.

What is claimed is:
 1. An insertion and guiding tool comprising acylindrical segment having an edge and a conical segment having an edge,the cylindrical segment and the conical segment connected together attheir edges to form a passageway adapted to guide a CIPP tubular linerinside a host pipe, wherein the cylindrical segment is made of a sheetmetal bent in the form of a ⅔ cylinder and the conical segment is madeof a sheet metal bent in the form of a ⅔ conical lip.
 2. The insertionand guiding tool of claim 1, wherein the cylindrical segment includes anopening and the conical segment includes an opening aligned with theopening of the cylindrical segment.
 3. The insertion and guiding tool ofclaim 1, further comprising at least one anchoring device adapted tosecure the tool onto an opening of a host pipe.